Thursday, November 21, 2013

Because I'm Impatient

As long as I had the cowling off to do my still secret project, I thought the time was ripe to install an oil preheater. This is a simple little device that does nothing more than provide an electric heat source to keep the oil at a reasonable temperature in the winter. There are a number of reasons to do so, ranging from protecting the engine during those first few minutes of running with cold, thick oil to saving engine wear and gas costs while waiting for the oil to heat from temps in the low teens to the required 120F before taking off. Those are valid reasons, but the primary reason is that I am impatient. I hate sitting there for twenty minutes waiting for the oil to heat up.

Being as the preheater kit is comprised of nothing more than a couple of electric heating pads and some wires to tie it all together, it seems the height of extravagance to pay $230 for it, but in the long run it's usually worth it. And installation is nothing more than gluing one of the heating pads and a thermostat to various places on the engine/oil tank - how hard could that be?

Right.

Harder than I ever expected.

"Harder" probably isn't the right word. It was more.... finicky.

First things first. In this case that meant putting a heating element on the oil tank. That actually was easy. It strapped right on around the circumference of the tank.

The next step was to glue a flat rectangular heating element to the bottom of the crankcase. That is a difficult location to get to, but by moving the oil cooler off to the side I was able to gain access. The first difficulty arose with the glue that was included with the kit. It's an epoxy glue, and it is shipped in what amounts to a plastic envelope. To mix the epoxy, we are instructed to roll a socket on top of the envelope for a lengthy amount of time to ensure a good mix. The glue is very thick, so it was hard to even tell if it was mixing at all. It was even harder to coerce it out of the envelope and onto the heating element. Finally, it was a challenge to find a way to hold the element in place for the 24-48 hours it would take the epoxy to set. I came up with this method using a spring clamp and a big socket:

Next was the installation of a thermostat, the function of which is to keep the oil from getting hotter than 150F. The thermostat is a small white tab at the end of a wire, and it gets glued to the bottom of the oil tank.

The glue was every bit as hideous for this application as it was for the first heating element. Basically it wanted to stick to everything but the oil tank. I grabbed a roll of masking tape to use to try to hold the thermostat in place while the glue cured. It was a three-hand job, but I have yet to be blessed with the evolutionary sprouting of such a handy (heh!) extra appendage.

C'mon, Darwin, do a bro a favah.

I glued the thermostat in place and held it with one hand while I tore off a strip of tape with the other. It was immediately apparent that a single piece of tape would not be sufficient, so I reached for the roll to tear off another, only to find.... nothing. I had to keep one hand on the thermostat lest it just fall off of the oil tank and hunt around for the tape with the other, but no matter where I looked... nothing.

I finally gave up and resigned myself to the fact that I would just have to let the thermostat fall off. I would have to clean the old glue off and try again, once I found that daggone tape.

Which.... took a long, long, LONG time.

I did eventually find it, though:

At that point, I decided that it would be prudent to get better tape. I ran home to get duct tape.

Fast forward 24 hours and there I was with Pete,ready to put the cowling back on. Just as we started, the thermostat fell off.

It was time for better glue, too.

The J-B Weld was called out by name in the installation instructions as a replacement for the G-D Hideous glue that came with the kit, but a dire warning came with it as well: it won't set up if the ambient temps are below 76F. They were. They will be for another four to five months.

Fine. It would just have to he heated. Finally, a use for those blasted incandescent spotlights.

Yet another 24 hours later, the glue had set up as strong as, uh.... a weld! J B would be proud!

After that it was just a matter of strapping down the wires. After what seems like a month of diddling around with this, that, and the other, it is finally ready to fly again!

1 comment:

Anonymous
said...

I wonder what it is about our genetic make-up that won't let us do these projects during the summer when conditions are right! I'm sure I'll be going through the same frustrations the winter after I get my RV-12 flying!

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